Clarias

Life-forms

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Superclassis/Classis: Actinopterygii
Classis/Subclassis: Actinopteri
Subclassis/Infraclassis: Neopterygii
Infraclassis: Teleostei
Megacohors: Osteoglossocephalai
Supercohors: Clupeocephala
Cohors: Otomorpha
Subcohors: Ostariophysi
Sectio: Otophysa
Ordo: Siluriformes

Familia: Clariidae
Genus: Clarias
Species: C. anfractus – C. anguillaris – C. batrachus – C. batu – C. brachysoma – C. cavernicola – C. dayi – C. dussumieri – C. fuscus – C. gariepinus – C. gracilentus – C. insolitus – C. intermedius – C. kapuasensis – C. leiacanthus – C. macrocephalus – C. magur – C. meladerma – C. microspilus – C. microstomus – C. monsembulai – C. nieuhofii – C. nigricans – C. olivaceus – C. planiceps – C. pseudoleiacanthus – C. pseudonieuhofii – C. serniosus – C. stappersii – C. sulcatus
Name

Clarias Scopoli, 1777: 455

Gender: masculine

Type species: Silurus anguillaris Linnaeus, 1758

Fixation: subsequent designation by Teugels & Roberts, 1987
Synonymy

Chlarias Scopoli, 1777: 455 [original spelling, regarded as in error, see CoF]
Macropteronotus Lacépède, 1803
Prophagorus Smith, 1939

References
Primary references

Scopoli, I.A. 1777. Introductio ad historiam naturalem sistens genera lapidum, plantarum, et animalium hactenus detecta, caracteribus essentialibus donata, in tribus divisa, subinde ad leges naturae. 540 pp. Apud Wolfgangum Gerle, Pragae [Prague]. BHL Reference page.
Teugels, G.G. & Roberts, T.R. 1987. Silurus anguillaris Linnaeus, 1758: designation as type species of Clarias Scopoli, 1777 and rediscovery of holotype (Pisces: Clariidae). Zoological Journal of the Linnean Society 90(1): 95–98.

Additional references

Hanssens, M. 2009: A review of the Clarias species (Pisces; Siluriformes) from the Lower Congo and the Pool Malebo. Journal of Afrotropical Zoology 5.
Ng, H.H.; Hong, D.K.; Nguyen, V.T. 2011: Clarias gracilentus, a new walking catfish (Teleostei: Clariidae) from Vietnam and Cambodia. Zootaxa 2823: 61–68. Preview (PDF)
Ng, H.H.; Hadiaty, R.K. Clarias microspilus, a new walking catfish (Teleostei: Clariidae) from northern Sumatra, Indonesia. Journal of Threatened Taxa 3(3): 1577–1584.
Ng, H.H. & Kottelat, M. 2014. Clarias serniosus, a new walking catfish (Teleostei: Clariidae) from Laos. Zootaxa 3884(5): 437–444. DOI: 10.11646/zootaxa.3884.5.4 Reference page.

Links

BHL bibliography
Clarias – Taxon details on Encyclopedia of Life (EOL).
Global Biodiversity Information Facility. 2019. GBIF Backbone Taxonomy. Checklist dataset. Taxon: Clarias.
ION
Nomenclator Zoologicus
Clarias species list in FishBase,
Froese, R. & Pauly, D. (eds.) 2024. FishBase. World Wide Web electronic publication, www.fishbase.org, version 02/2024.
Clarias and its species (including synonyms) in Catalog of Fishes, Eschmeyer, W.N., Fricke, R. & van der Laan, R. (eds.) 2024. Catalog of Fishes electronic version.
ITIS

Vernacular names
English: Walking catfish
ไทย: ปลาดุก

Clarias liocephalus

Clarias is a genus of catfishes (order Siluriformes) of the family Clariidae, the airbreathing catfishes. The name is derived from the Greek chlaros, which means lively, in reference to the ability of the fish to live for a long time out of water.[1]
Taxonomy

Clarias has been found to be paraphyletic. A species of Heterobranchus (H. longifilis) clusters deeply inside the Clarias group.[2]
Distribution

They are found in inland waters throughout much of the Old World, and are one of the most widespread catfish genera in the world.[3][4] The genus is found in Southeast Asia and East Asia westwards through India and the Asia Minor to Africa.[5] The diversity of these catfishes is highest in Africa.[6] Some (notably the walking catfish) have become pest species where they have been accidentally introduced, and particularly in Cuba, where their introduction was intentional.
Description

Clarias species are recognized by their long-based dorsal and anal fins, which give them a rather eel-like appearance. These fish have slender bodies, a flat, bony head, and a broad, terminal mouth with four pairs of barbels. Many species also have a large, accessory breathing organ composed of modified gill arches.[3][5] Also, only the pectoral fins have spines.[7]
Species

There are currently 62 species recognized in this genus:
African species

Clarias agboyiensis Sydenham, 1980
Clarias albopunctatus Nichols & La Monte, 1953
Clarias alluaudi Boulenger, 1906 (Alluaud's catfish)
Clarias angolensis Steindachner, 1866
Clarias anguillaris Linnaeus, 1758 (mudfish)
Clarias buettikoferi Steindachner, 1894
Clarias buthupogon Sauvage, 1879
Clarias camerunensis Lönnberg, 1895
Clarias cavernicola Trewavas, 1936 (cave catfish)
Clarias dhonti Boulenger, 1920
Clarias dumerilii Steindachner, 1866
Clarias ebriensis Pellegrin, 1920
Clarias engelseni Johnsen, 1926
Clarias gabonensis Günther, 1867
Clarias gariepinus Burchell, 1822 (North African catfish)
Clarias hilli Fowler, 1936
Clarias jaensis Boulenger, 1909

Clarias laeviceps T. N. Gill, 1862
Clarias laeviceps dialonensis Daget, 1962
Clarias laeviceps laeviceps T. N. Gill, 1862
Clarias lamottei (?) Daget & Planquette, 1967 [8]
Clarias liocephalus Boulenger, 1898 (smoothhead catfish)
Clarias longior Boulenger, 1907
Clarias maclareni Trewavas, 1962
Clarias macromystax Günther, 1864
Clarias monsembulai Bernt and Stiassny, 2022 [9]
Clarias ngamensis Castelnau, 1861 (blunt-toothed African catfish)
Clarias nigromarmoratus Poll, 1967
Clarias pachynema Boulenger, 1903
Clarias platycephalus Boulenger, 1902
Clarias salae Hubrecht, 1881
Clarias stappersii Boulenger, 1915 (blotched catfish)
Clarias submarginatus W. K. H. Peters, 1882
Clarias theodorae M. C. W. Weber, 1897 (snake catfish)
Clarias werneri Boulenger, 1906 (Werner's catfish)

Asian species

Clarias abbreviatus Valenciennes, 1840
Clarias anfractus H. H. Ng, 1999 [10]
Clarias batrachus Linnaeus, 1758 (Walking catfish)
Clarias batu K. K. P. Lim & H. H. Ng, 1999 [5]
Clarias brachysoma Günther, 1864
Clarias cataractus Fowler, 1939
Clarias dayi Hora, 1936
Clarias dussumieri Valenciennes, 1840
Clarias fuscus Lacépède, 1803 (Hong Kong catfish)
Clarias gracilentus H. H. Ng, K. H. Dang & V. T. Nguyen, 2011 [11]
Clarias insolitus H. H. Ng, 2003 [3]
Clarias intermedius Teugels, Sudarto & Pouyaud, 2001 [6]
Clarias kapuasensis Sudarto, Teugels & Pouyaud, 2003 [12]
Clarias leiacanthus Bleeker, 1851
Clarias macrocephalus Günther, 1864 (bighead catfish)
Clarias magur F. Hamilton, 1822
Clarias meladerma Bleeker, 1846 (blackskin catfish)
Clarias microspilus H. H. Ng & Hadiaty, 2011 [13]
Clarias microstomus H. H. Ng, 2001 [4]
Clarias nebulosus Deraniyagala, 1958
Clarias nieuhofii Valenciennes, 1840 (slender walking catfish)
Clarias nigricans H. H. Ng, 2003 [14]
Clarias olivaceus Fowler, 1904
Clarias planiceps H. H. Ng, 1999 [10]
Clarias pseudoleiacanthus Sudarto, Teugels & Pouyaud], 2003 [12]
Clarias pseudonieuhofii Sudarto, Teugels & Pouyaud, 2004 [7]
Clarias serniosus H. H. Ng & Kottelat, 2014 [15]
Clarias sulcatus H. H. Ng, 2004

Fossil species

Clarias falconeri † Lydekker, 1886, from India

Importance to economy
Yam pladuk fu (Thai: ยำปลาดุกฟู): shredded and deep fried Clarias (pla duk) catfish with salad
Pecel lele, an Indonesian-style deep fried Clarias (lele); usually sold as street food

Many of the species are of great economic importance in both fisheries and fish culture.[6]
Invasive species

Clarias catfish and primarily Clarias batrachus (walking catfish) have been introduced to many different areas of the world, where they are causing problems for the native wildlife. The effect of introduction of these fish varies from area to area, but as they are predatory, they often affect the local wildlife by eating other fish, birds, and amphibians. In Florida, the fish are causing problems by invading aquaculture farms and preying on the fish cultivated there.[16] Countries where one or several Clarias species have been introduced include Indonesia, the United States, Hong Kong, China, UK, Papua New Guinea, Guam, Taiwan, Thailand, and Cuba.
References
Wikimedia Commons has media related to Clarias.

Froese, Rainer and Pauly, Daniel, eds. (2011). Species of Clarias in FishBase. December 2011 version.
Mwita, CJ; Nkwengulila, G. (2008). "Molecular phylogeny of the clariid fishes of Lake Victoria, Tanzania, inferred from cytochrome b DNA sequences". Journal of Fish Biology. 73 (5): 1139–1148. doi:10.1111/j.1095-8649.2008.01935.x.
Ng, Heok Hee (2003). "Clarias insolitus, a new species of clariid catfish (Teleostei: Siluriformes) from southern Borneo" (PDF). Zootaxa. 284: 1–8. doi:10.11646/zootaxa.284.1.1. Retrieved 2009-06-24.
Ng, Heok Hee (2001). "Clarias microstomus, a New Species of Clariid Catfish from Eastern Borneo (Teleostei: Siluriformes)" (PDF). Zoological Studies. 40 (2): 158–162. Archived from the original (PDF) on 2011-07-19. Retrieved 2009-06-24.
Lim, Kelvin K. P.; Ng, H. H. (1999). "Clarias batu, a New Species of Catfish (Teleostei: Clariidae) from Pulau Tioman, Peninsular Malaysia" (PDF). The Raffles Bulletin of Zoology (6): 157–167. Archived from the original (PDF) on 2011-06-06. Retrieved 2009-06-24.
Teugels, Guy G.; Sudarto; Pouyaud, Laurent (2001). "Description of a New Clarias Species from Southeast Asia Based on Morphological and Genetical Evidence (Siluriformes, Clariidae)" (PDF). 25 (1): 81–92. Archived from the original (PDF) on 2010-12-26. Retrieved 2009-06-24. {{cite journal}}: Cite journal requires |journal= (help)
Sudarto; Teugels, Guy G.; Pouyaud, Laurent (2004). "Description of a New Clariid Catfish, Clarias pseudonieuhofii from West Borneo (Siluriformes: Clariidae)" (PDF). Zoological Studies. 43 (1): 8–19. Archived from the original (PDF) on 2018-06-13. Retrieved 2009-06-24.
Guy G. Teugels (2003). "Clarias lamottei (Siluriformes, Clariidae), a Naturel Intergeneric Hybrid from West Africa" (PDF). Cybium 2003, 27(1): 11-15. Teugels, Guy. Retrieved 12 April 2023.
Maxwell J. Bernt & Melanie L.J. Stiassny (2022). "A New Species of Air-Breathing Catfish (Clariidae: Clarias) from Salonga National Park, Democratic Republic of the Congo". American Museum Novitates 2022(3990). Bernt, Maxwell J. & Stiassny, Melanie L.J. Retrieved 11 April 2023.
Ng Heok Hee (1999). "Two New Species of Catfishes of the Genus Clarias from Borneo (Teleostei: Clariidae)". Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore. H. H. Ng. Retrieved 11 April 2023.
Ng, H. H.; Dang, K. H. & Nguyen, V. T. (2011). "Clarias gracilentus, a new walking catfish (Teleostei: Clariidae) from Vietnam and Cambodia" (PDF). Zootaxa. 2823: 61–68. doi:10.11646/zootaxa.2823.1.4.
Tomy Sudarto; Guy Teugels & Laurent Pouyaud (March 2003). "Description of two new Clarias species from Borneo (Siluriformes, Clariidae)". Cybium. Tomy Sudarto, Guy Teugels, & Laurent Pouyaud. Retrieved 11 April 2023.
Ng HH & Hadiaty Rk (2011) Clarias microspilus, a new walking catfish (Teleostei: Clariidae) from northern Sumatra, Indonesia. Journal of Threatened Taxa 3(3): 1577-1584. http://www.threatenedtaxa.org/ZooPrintJournal/2011/March/ng.htm Archived 2012-03-22 at the Wayback Machine
Ng, Heok Hee (2003). "Clarias nigricans, a New Species of Clariid Catfish (Teleostei: Siluriformes) from Eastern Borneo" (PDF). The Raffles Bulletin of Zoology. 51 (2): 393–398. Archived from the original (PDF) on 2009-02-19. Retrieved 2009-06-24.
Ng, H.H. & Kottelat, M. (2014): Clarias serniosus, a new walking catfish (Teleostei: Clariidae) from Laos. Zootaxa, 3884 (5): 437–444.
issg Database: ecology of Clarias batrachus